NEW YORK (AP), Nov 01 - The Wall Street Journal remains the No. 1 newspaper in the U.S with average weekday circulation of 2.1 million, according to the Audit Bureau of Circulations.

Gannett Co.'s USA Today ranks second with 1.8 million, and The New York Times is third with 1.2 million on average from Monday to Friday. The latest figures, covering the six months that ended Sept. 30, were released Tuesday.

The Times' circulation grew after it started charging online fees or requiring a print subscription for full access to its website and mobile services. That began just before the start of the latest circulation reporting period. Digital subscriptions are included in the circulation totals.

The Times had the highest circulation on Sundays with 1.6 million. Neither the Journal nor USA Today publishes on Sundays.

Circulation has been declining at newspapers in part because readers are shifting from printed editions to free news sources on the Web and on mobile devices. For most newspapers, digital subscriptions have not caught on. The exceptions are primarily publications with national clout.

During the April-September period, the Times had average weekday digital circulation of 380,003 and Sunday circulation of 371,933. News Corp.'s Journal had a weekday average of 537,469.

The latest circulation numbers are not comparable with those from the same period last year because of new rules governing what counts as circulation.

Among other things, the changes have made it easier for newspapers to lump separate editions under different titles into one total. They also allow some copies that are distributed free of charge to be tallied. Digital editions, though, were counted even before the rule changes.

Compared with the October-March period, which had the same rules as the latest period, the Times saw its circulation grow 25 percent, primarily because of the new digital policies. Many Americans opted to buy a print subscription because it comes with free digital access; others simply paid for online access.

Circulation figures affect advertising rates at newspapers, which count print ads as their main source of revenue. Print ad revenue has also been falling in recent years as readers and advertisers shift to the Internet. The economic downturn has exasperated the decline. Some newspapers have seen growth in digital ad revenue, but it hasn't been enough to offset the losses in print.